<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div id="app">
        <div class="box">
            <h3>小黑自动售货机</h3>
            <button @click="buy(5)">可乐5元</button>
            <button @click="buy(3)">雪碧3元</button>
        </div>
        <p>余额：{{money}}</p>
    </div>
    <script src="https://cdn.jsdelivr.net/npm/vue@2.7.16/dist/vue.js"></script>
    <script>
        const app = new Vue({
            el:'#app',
            data:{money:100},
            methods:{
                buy(price){
                    this.money -= price
                }
          }      
        })
    </script>
</body>
</html>